Detonative element of apparatus for sinking wells by means of explosive charges



May 17, 1960 L. BORINS ETAL DETONATIVE ELEMENT 0F ARA'IUS FOR SINKING WELLS CHARGES APP BY MEANS OF EXPLOSIVE Original Filed Feb. 21, 1957 15 Sheets-Sheet '1 m GE m afi n sdm m w m w S T A B d xk WM L M m B May 17, 1960 L. BORINS ET 2,935,708

AL DETONATIVE ELEMENT OF APPARATUS FOR SINKING WELLS BY MEANS OF EXPLOSIVE CHARGES Originayl Filed Feb. 21, 1957 15 Sheets-Sheet 2 Fig.3.

74 INVIQNTUU/ Lows Borms,

BY Maurjcalf. SJUdci I MGEEICQJ Zublr ofii 2 Y AT RNEX May 17, 1960 1.. BORINS ETAL 2,936,708

DETONATIVE ELEMENT 0F APPARATUS FOR SINKING WELLS BY MEANS OF EXPLOSIVE CHARGES Original Filed Feb. 21, 1957 15 Sheets-Sheet 3 Fig.4. 25 4 Low; r :25, BY MaunceHSJud (S A Mu eubkoff TTORNEY.

May 17, 1960 L. BORINS ETAL 2,936,708

omoumvs ELEMENT 0F APPARATUS FOR smxmc WELLS BY MEANS OF EXPLOSIVE CHARGES Original Filed Feb. 21, 1957 15 Sheets-Sheet 4 93 EN To):

L011 fins, MauncaliSludl Mau 'caZZubJrofij B ATTORNEI T May 17, 1960 BORINS ETAL ,7 8

DETONATIVE ELEMENT OF APPARATUS FOR smxmc WELLS BY MEANS OF EXPLIOSIVE CHARGES Original Filed Feb; 21, 1957 15 Sheets-Sheet 5 uvmyrons L0u1s Borms, BY flaurgcelisjud Mau ceJZukoff,

WUIATTORNEY May 17, 1960 L. BORINS ETAL 2,936,

DETONATIVE ELEMENT OF APPARATUS FOR SINKING WELLS BY MEANS OF EXPLOSIVE CHARGES Original Filed Feb. 21, 1957 15 Sheets-Sheet 6 20 20" Q 74 68 F1 Q. 7. 1Q

INVENTORS L0 1115 Borms, BY Maurgcefislud Ma unceJ. Z ubkoff,

TTORNEY y 7, 1960 L. BORINS ETAL 2,936,708

DETONATIVE ELEMENT 0F APPARATUS FOR SINKING WELLS BY MEANS OF EXPLOSIVE CHARGES Original Filed Feb. 21, 1957 15 Sheets-Sheet 7 WWW nvmyrons Lows .Borms, BY MauriceH. Slud l rrc'el Zubkofi, WATTORNEK May 17, 1960 L. BORINS ETAL 2,936,708

DETONATIVE ELEMENT OF APPARA'I'US FOR smxmc WELLS BY MEANS OF EXPLOSIVE CHARGES Original Filed Feb. 21, 1957 15 Sheets-Sheet a 9 ATTORNEY.

y 7, 1960 BORINS ET AL ,70

DETONATIVE ELEMENT OF APPARATUS FOR SINKING WELLS BY MEANS OF EXPLOSIVE CHARGES Original Filed Feb. 21, 1957 15 Sheets-Sheet 9 INVENIOR. Lows Borms, BY MULLTICQH 11d,

Maur'ce J. Zubkoff Wa ATTORNEY.

I May 17,1960 L BQRINS ETA 2,936,708

. L DETONATIVE ELEMENT OF APPARATUS FOR SINKING WELLS BY MEANS OF EXPLOSIVE CHARGES Original Filed Feb. 21, 1957 15 Sheets-Sheet 10 2 uvwzgvroxs 90 1 Lows 150111125 BY MauriceHSlud 6L May 17, 1960 1.. BORINS ET AL 2,936,7 8

DETONATIVE ELEMENT OF APPARATUS FOR smxmc WELLS BY MEANS OF EXPLOSIVB CHARGES Original Filed Feb. 21, 1957 15 Sheets-Sheet 11 NVENTORS LOUIS Barms, 1 BY Maurice/i Slud 5 Ma iceJZubkoff,

May 17, 1960 L. BORIN ET AL 2,936,708

DETONATIVE ELEMENT 0F APP TUS SINKING WELLS BY MEANS OF EXPLOSIVE RGES Original Filed Feb. 21, 1957 15 Sheets-Sheet 12 Fig). 24. la 125. Ma g 16 o. 125 I Y p u if 106 ,105 no 01 407 m .1" M6 1171 8 INV .TORS

Lows Borms, MauriceHflud &

au 'cQJ. Zubkoff,

W ATTORNEY.

May 17, 1960 L. BORIN ETAL 2,936,703

DETONATIVE ELEMENT 0F APP 'rus szuxmc WELLS BY MEANS OF EXPLOSIVE RGES Original Filed Feb. 21, 1957 ,15 Sheets-Sheet 1s 64 1 I v:- III/I/ III'II/IIAV/Il mvuvzons Lou]; Borms, BY Mauncoh. Sludl ATTORNEY May 11, 1960 936,708

L. BORINS ET AL DETONATIVE ELEMENT OF APPARATUS FOR SINKING WELLS BY MEANS OF EXPLOSIVE CHARGES Original Filed Feb. 21, 1957 15 Sheets-Sheet 14 154 155 INVENTOIQS Louis Borjns. BY MaurjceJiSJudZ Ma 16 .Zublroffl Q ATTORNEY-L May 17, 1960 1. BORINS ET AL 2,936,7 8 DETONATIVE ELEMENT OF APPARATUS FOR SINKING WELLS BY MEANS OF EXPLOSIVE CHARGES Original Filed Feb. 21, 1957 15 Sheets-Sheet l5 k316P166 16U 70151 168170 169 143 I M I W/ WI {Imus Lows Borms, BY MauriceJiSJud Ma ice .Zubkoff, I

Un t d States Pat w DETONATIVE ELEMENT 0F APPARATUS FOR SINKING WELLS BY MEANS OF ExPLosIvE CHARGES 1 8 Claims." C1. 102

'This application is a division of 'our application Serial No. 638,749 uponfwhich Patent No. 2,898,085 was issued on August 4, 1959, this patent being directed to Appar'atus for Sinking Wells by Means of Explosive Charges. The method of sinking wells "which is practicedby the apparatus of the parent application forms the subject of Patent'No. 2,897,756 which was issued on August 4, 1959 pursuant to a'division'al application, Serial No. 647,716. The apparatus and -method utilize shaped charges of novel and advantageous character, blasting charges, and carriers severally for the shaped chargesand blasting charges, each carrier beingcomposed of frangible material that is shattered -by the detonation of its associated charge and being also ofnovel and advantageous vcharacter.

This invention relates to "the detonative element of apparatus for sinking wells by .means .of 'expljosive charges, the element being characterized by the novel carriers for the charges as ,articlesof manufacturejr the shaped charges of novel form as articles of manufacture, and the novel combination of the. carrier and the' explosive charges, including both the shaped charges andblasting charges. H V V -In order that the utility and advantages of the invention may clearly appear the invention is necessarily disclosed in connection with the apparatus and method which forms the subjects of said Patents Nos. 2,898,085 and 2,897,756.

The method, which forms the subject of said Patent No. 2,897,756, in a single cycle of'operation utilizes a {plurality of shaped charges which are included in the subject of the present application and are mounted'in frangible charge carriers which are shattered bythe detonation. The shaped charges are'sequentially detonated,

each having a multiplicity' of directionalizing recesses,

preferably uniformly distributed, the method being available for advancing the well bore from the'surface and including the use of blasting charges also'mounted in generally similar frangible charge carriers and arranged in relation to the shaped charges aslpa'rts of a series of explosive charges, the blasting charges being detonated fin sequential'relation to the shaped'charges, The method also includes-provisions during the period of' thedetonations for flushing from the-well bore the detritus re- 'sultant from the detonations; The frangible charge car- 5 Y 'riers, both-for the shaped charges and'forthe blasting charges, are likewise included in the subject of the present application.

The invention which forrristhc subject of the present application includes a unitary explosive charge carrier--- for use with the apparatus shown insaid Patent No. 2,898,085. Accordingto the invention the carrier is composed of suitable frangible material, preferably dielectric and preferably molded from a thermosetting plastic such as rubber or 'a 'phenol condensation product,

the carrier is also fashioned to position the charge in proper stand-off relation to the target. In the case,of

blasting charges the charge may be supported by the carrier for deposit closely adjacent or in substantially adjoining relation to the target. The carriers are preferably constructed whereby they may be arrangedfin nested relation in the magazine.

Each charge carrier is of generally annular the part which projects above the explosiveTcharg'eis utilized for its support in the magazine and in the charge transfer means. Each carrier for a shaped chargefincludes a charge-supporting web located at an intermediate elevation andwhich also protects the chargefagainst water, either as used for flushing or as encountered in the well sinking operation. Each carrier for a blasting charge preferably includes a similar web located ator near its lower end. In the case of shaped charges each carrier is formed with an annular skirt which projects for a suitable distance below the web and rests upon the target, thereby to position the charge in the appropriate stand-off relation to the target. Each carrier includes an annular vertical wall which in the construction preferred is of externally tapering outline and is otherwise formed to receive in nesting relation the lower portion of the carrier immediately above. The invention also includes a shaped chargeof novel and advantageous construction which is of wafer-like form and is characterized by a multiplicity of uniformly distributed downwardly facing directionalizing recesses which simultaneously generate penetrating jets. The term shaped charge is. intended to cover both an integral body of suitable explosive material and a series of small bodies of such material, each having an individual directionalizing recess, the smallbodies being embedded iira supporting frame of plastic material mounted on the shelf of the carrier and being separatedfrom one another by webs of the plastic materialof-the frame. Theshaped charges may be said to be wafer-like in that in thickness they are quite shallow as compared withfshapedcharge's 2 heretofore known for well sinking Orwell shooting 'and the area through which the directionalizing recessesfarc distributed is many times in excess of the thicknessflji'o'gf the charge. The penetrating jets resultant from the distance. It is preferred, and in accordance with lthc invention, that the recesses adjacent the periphery of the charge have their axes at a very Slightoutward-Qa'nd downward inclination, e.g., of the order of one or two degrees in order to insure that the diametrical dimension of the well bore shall be. ample for thefree movement of the apparatus. Beyond the distance of efiectiye pehetration there will be a series of tapering openings whereby the bottom of the wellbore willpresent aseries ofridges which are obliterated by' the succeeding detonation, either of a shaped charge or a blastingcharge. 'Thegsize and weight of the shaped charges are determined in accordance with the particular local conditions that may "be encountered. Generally speaking, the diametrical dimension is of the order of 'five and one-half. inchesandithe thickness or depth is a range'ofthe orderof from 'one half inch to somewhat more'than two inches; An

integral shaped charge ,Qf one-half inch fdepth"has*'a Pli m uaviz use I.

manna.

weight of the'order of one-half pound and the maximum weight for charges of greater depth, with allowance for the increase in the dimensions of the directionalizing recesses, is of the order of one pound. Theblasting charges are in the form of an integral body of'explosive material and, according to local conditions, have a depth within a range of the order of onehalf inch to one inch and a weight within a range of theorder of one-half pound to one pound.

When the stratum of oil bearing sands is reached it may be of economic advantage, depending upon local conditions, to increase the diameter of the well bore. For this purpose shaped charges are used ha'ving periph- 'eral directionalizing recesses with their axes directed laterally in addition to the multiplicity of directionalizing recesses open to the lower face of the charge with the result that upon detonation the well bore is both deepened and widened. With shaped charges having a diametrical dimension of the order of five and one-half inches the well bore within the cap-rock and the overlying earth will have a diameter somewhat in excess of six inches. The increase of the diameter in the oil bearing stratum may be in excess of twice the diameter of the well bore in the overlying mass.

The shaped charges, preferably, but not necessarily, of any suitable high brisance material, are detonated, in accordance with known practice, by an initiating charge activated by the ignition (from electrical sources) of an explosive fuse such as primacord, the initiating charge as associated with a shaped charge of integral character being preferably of disc outline and arranged within the fuse in adhering relation to the explosive charge. Each explosive charge is detonated by a delay type igniter following its deposit upon the target and during the return movement of the charge transfer means.

The charges (shaped and blasting) used in the normal sinking of the well bore may be preformed independently of the carriers and, being malleable under heat, thereafter fitted in the carriers. However the preferred practice is to incorporate them with the carriers during the molding operation. The recesses of the shaped charges are preferably formed by metal or other liners of corresponding shape which, at the inception of the molding operation, are supported in accordance with established plastic molding technique by temporary rods resting upon the base of the mold. The shaped charges used for sinking and expanding the well bore in the oil bearing stratum are preformed and thereafter fitted in the recesses of the carriers.

In the drawings:

Figures 1 to 1d inclusive are schematic views illustrating the successive steps of operation involved in the detonation of an initial shaped charge when hard impervious rock stratum is encountered.

Figure 1 is an elevation, partly in section, which assumes the formation of the well bore to the point where hard impervious rock stratum is encountered and shows the apparatus at the time of the initial contact of the charge transfer means, then empty, with the target, i.e., the hard rock stratum.

Figure 1a is a fragmentary elevation, partly in section, which shows the apparatus with the shell in the position shown in Figure 1 but with the charge transfer means, immediately following its initial contact with the target, in its uppermost position in which it has received the lowermost charge carrier from the magazine.

Figure 1b is a similar fragmentary elevation, partly in section, which shows the apparatus with the shell in the position shown in Figure 1 but with the charge transfer means, bearing a charge carrier, in its lowermost position in which the charge carrier is deposited upon the hard rock stratum for detonation of the charge.

Figure 1c is a similar fragmentary elevation, partly in section, which shows the apparatus with the shell in the position shown in Figure 1 at the time when the charge transfer means, having deposited the charge carrier upon the target for detonation of the charge, is in movement to its uppermost position to receive a succeeding charge carrier from the magazine, the deposited charge carrier being shown resting upon the target.

Figure 1d is a similar fragmentary elevation, partly in section, which shows the apparatus with the shell in the position shown in Figure 1 but with the charge transfer means in its uppermost position and as having received a succeeding charge carrier from the magazine, this figure assuming the detonation of the preceding charge and showing the resultant extension of the well bore intothe hard rock stratum.

Figure 2 is a fragmentary elevation, partly in section, which assumes the detonation of a preceding charge and the downward movement of the apparatus for a distance corresponding to the resultant extension of the well bore with the shell and the charge transfer means in the same relation to one another and to the hard rock stratum which is shown in Figure 1b, it being understood that the immediately succeeding steps of operation are in accordance with the showing of Figures 10 and 1d.

Figures 3 and 4, considered conjointly, show the apparatus in vertical central section, Figure 3 showing the upper portion of the apparatus and Figure 4 it lower portion with the explosive charge transfer means in its raised position relatively to the shell. 7

Figure 5 is a partial vertical central section of the apparatus with the explosive charge transfer means in its lower position relatively to the shell.

Figure 6 is a horizontal section on the line 6-6 of Figure 3 with a cover plate partly broken away to expose to view certain underlying parts.

Figure 7 is a horizontal section on the line 77 of Figure 3.

Figure Figure 3.

Figure 9 is a horizontal section on the line 9-9 of Figure 4.

Figure 10 is a horizontal section on the line 10-10 of Figure 4.

Figure 11 is a horizontal section on the line 11-11 of Figure 4.

Figure 12 is a horizontal section on the line 12-12 of Figure 4.

Figure 13 is a partial vertical diametrical section on an enlarged scale of the shaped charge carrier and the shaped charge, together with the lower portion of the charge transfer means.

Figure 14 is a similar view in which the carrier is formed for the support of a blasting charge, the plane of the section being sixty degrees distant from the plane of the section shown in Figure 13.

Figure 15 is a perspective sectional view of one of a plurality of similar valves by which air as the operating fluid is admitted into the pressure way above the charge transfer means.

Figure 16 is an enlarged fragmentary vertical sectional View in the same plane as Figure 5 showing in closed position certain spring biased valves associated with air flow passages. V

Figure 17 is a View similar to Figure 16 but showing the same valves in their open or by-passing positions.

Figure 18 is a fragmentary horizontal view in the same plane as Figure 11 and showing in its releasing position one of a plurality of detents associated with the magazine and which normally engage the lowermost charge carrier as the support for the series of charge carriers.

Figure 19 is a fragmentary sectional perspective view with the upper and intermediate shell sections in separated relation and showing more particularly their companion connecting elements and the electrical contacts at the lower end of the upper shell section and the upper end of the intermediate shell section.

Figure 20 is a detail perspective view, partly in section,

8 is a horizontal section on the line 8-8 of ingcharge andits carrier.

charge shown in Figure 27.

33 33 of Figure'32. "Figure 34 is 'a partial central transverse section of a shaped charge which is formed to enlarge the well bore in the stratum of oil bearing sands, the showing of actuated delay type igniter.

ega'segvo'e Figure 22 is a detail perspective view of the charge transfer means.

Figure 23 is a detailfragmentaryperspective view partly broken away and showingthe relationship between the lower portion of the shell and of the sleeve in surround- I ing relation to the shell and .whichdelimits an annular way; external of the shell in which the, charge transfer earrier is movable.

. Figure 24. is awiring diagram showingthe detonating circuit as conditioned to effect the detonation.. a

; .Figure 25 is adeveloped vertical section showing eleca.

' ti ical cable. sections in the several. shell .s ec tions and the charge. transfer means and also showing the electrical connections between the wires. :Figure 26 is a vertical section in a plane radially inters ecti-ng the. section shown in Figure 25.

. Figure 27 is a central transverse section of' an embodi-,-

ment of the invention, comprising a sha edchargeand its carri'enthis figure. assuming that the charge is an intea Figure 28 is a central transverse section of an embodi r n'ent of the invention for use in association with the embodiment shown in Figure 27 andcomprising a blast- I; Figure 29 is. a partial bottom plan I 7 view of' 'the shaped j F -igure 30 1s a partial plan view of a shaped charge consisting ofan integral body ofexplosive material wherein the directionalizing feature consists of concentric grooves i of inverted V -shape in section.

'1 Figure' 3l is' a partial transverse sectional view on the line 31 '31of" Figurje"30;

Figure 32 is a bottom'plan view' of a shaped charge consisting of an'integral body of explosive material wherein the directionalizing feature. consists of radially arranged grooves of inverted V-shape insection. V

Figure 33 is' a partial transverse section on the line the shaped charge in this figure'being' applicable either to. conical recesses or annular grooves as'the directional? i'zing feature. Figure '35 is'a partial side elevation of'a shaped charge formed to enlarge the wellbore in' the stratum of oil bearing .sands i and wherein the 'directionalizing feature for ssinking the well bore vertically consists of the radial grooves shown in Figures 32 and 33.

-.Figure 36 is a plan view'of, a shaped. charge which shows more particularly the form offlthe explosive fuse and its relation to the initiating charge and'the electrically Figure 37 is a plan view, with the cover partly broken away, of a shaped charge composed of a series of small bodies of explosive material embeddedin a plastic frame and each havinganindividual directionalizing recess.

[Figure 38 is a sectional view on an enlarged scale on the line 3838 of Figure 37, this figure also showing by E broken lines the mounting of the charge in the charge carrier. a I a p The operating unit of the apparatus includesv a shell 1 of; cylindrical form which'carriessundry associated parts posedrelation and provided in a predetermined 7 The shell is preferably composed of upper, intermediate I sections 1b and 1c conjointly provide the magazine, and

the sections 1b are made of varying lengths from which a selection may be made in order that'the magazine capacity may be in accordance with prevailing conditions.

The shell 1 (Figure 3) is detachably connected at its upper end to a top plate 5 and is raised andlower'ed by means of cables 6 having terminal loops 7 threaded through eye members 8 bolted as at 9 to thetopplato 5. The movable parts o-f'the operating'unit are power actuated, preferably by compressed air conveyed from an; external source by a flexible hose 10 having a suite able connection 11 externally of the unit to a pipe section 12 which extends into the unit through the plate 5.

The flushing of the rock detritus is preferably effected v by a flushingfluid of any suitable character which for brevity and convenience is herein referred to as water. The water is pumped under suitable pressure from a source at the surface and is conveyed by a flexible hose 13 having a suitable connection 14 externallyjof the unit to a pipe section 15 which extends into the unit through theplate 5. The cable 16 for the electric wires of the circuit by which the squib is ignited extends into the .unit throughthe top plate 5. The section 1a carries in detachable relation a distributor 17 for theair conveyed by the hose 10 and the water conveyed by the hose 13. I i

The distributor 17, in the form of'a cylindrical block; is formed with a vertical passage 18 which may be called a supply passage for the operating fluid. Thepassage 18' is in open communication at its upperend with the pipe section 12 and at its 'lower end with ahorizontal continuation 19 which extends. radially .to, and communicates with, an opening 37 located centrally of the distributor 17. The opening 37, as willbe later described in detail, forms part of a flow passage from which air under pressure is delivered into the pressure space; F at the upper end of the magazine M in which theexplosive charges are arranged. The opening 37 is also utilized as a manifold for the distribution of air viaradialpas'e v sages (Figure 7) 20a, 20b, 20c, 20d and.i20e to a numr ber of vertical air flow passages formed in the wall of the shell and which will be described in detail at .alater point. A, passage 21 of-similar function extends=radially outward from the passage 18 and communicates with one of the vertical airflow passages inthe shell'fl 'Ihe distributor 17 (Figure :3 has a recess in its upperface which provides a water; inlet chamber 22' closedbya cover plate 23 fitted in'a countersunk recess and secured in any suitable manner, as by spot welding. The pipe' section 15 is connected to thecover plate 23 and is nor mally in open communication wtih the chamber 22;

The cables 6 in their functions of raising, lowering and supporting the-operating unit are controlled byfa cated at the surface. Since the air hose 10, water hose 13 and cable 16 differ in diameter from: one another and from the cables 6 any suitable provision 'is made in accordance with known engineering practice for'coordinating the rate of rotation of their reels to therate 7 of rotation of the Windlass" for the cables 6 whereby these several flexible elements will have-the:sa'me-rateof upward and downward movement.

' The water inlet chamber 22 discharges a mies. I

of passages 24 in the distributor 17 into a verticafflushpipe 25 detachably connected to the distributor 17 from which it extends for the remaining length of the unit, the :pipe 25 being open at its lower end and of any suitable diameter, e.g., the same diameter as the hose 13 and pipe section 15. The water is pumped under suitablepressure through the hose 13 and pipe section 15 and, discharging from the pipe 25, flows into the lower end of the well bore W whence, carrying with it in suspensionthe fragmented and pulverized rock detritus, it flows upward to the surface through the space S between the well bore and the unit, being conveyed at the surface to a disposal basin (not shown).

The gallonage of water required per unit of time for the flushing operation will, of course, vary with different operating conditions including the depth at which the unit may be working. The amount of water required or proper for a particular operating condition is determined by a suitable flow regulating valve. As shown, and now considered preferred, the water flow regulating valve (Figures 3 and 6) consists of a plate 26 of disc form mounted for turning movement about its axial center upon the base of the inlet chamber 22 and having openings 27 for total or partial registry with the upper ends of the passages 24, the amount of water delivered to the pipe 25 being proportionate to the degree of registry. The positional adjustment of the valve 26 is made in accordance with prevailing conditions, at any position of the unit in the well bore, preferably by an electric motor 28 mounted upon the cover plate 23. The regulation of the flow of flushing water through the pipe 25 by the adjustment of the position of the valve 26 as incorporated with the unit results in the rate of flow of flushing water through the pipe 25 being determined independently of friction losses in the water supply hose 13. The shaft 29 of the motor 28 extends into the water inlet chamber 22 and is journalled at its lower end in the distributor 17, the shaft carrying a spur gear 30 adjacent the base of the chamber 22. The plate 26 is formed with aseries of peripheral teeth 31 (Figure 6) in mesh with the spur gear 30. The position of the plate 26 is indicated to the operator at the surface by a dial mechanism (not shown) in electrical association with the motor 28, the form of the dial mechanism and the manner of its electrical association with the motor being well known for use where the positional adjustment of a concealed part is to be indicated to the operator in charge. The dial mechanism, of course, informs the operator of the prevailing adjustment of the position of the plate 26 and enables him to determine the direction and extent of its movement when a change may be required in the gallonage of water flowing through the pipe 25.

In the event that a back pressure should be encountered sufliciently high to cause resurgence of the water in the pipe section 15 and hose 13, or otherwise to put an undue load on the pump, it is desirable that the flow of water be cut off until the condition is relieved. For this purpose a check valve 32 (Figure 3) islocated in alining relation below the lower end of the pipe section 15 and urged upward by a loading spring '33, Figure 3 assuming the valve 32 to be held open by the pressure of the water discharging from the pipesection 15. The valve 32 has a central depending stem 34 which provides a pivot about which the valve 26 may be turned and, projecting through a central opening in the valve, is fitted loosely in a recess in the distributor 17. The pressure of the spring 33 may be relied upon to hold thevalve 26 in seated relation upon the base of the recess 22.

The shell parts 1b and 1c conjo-intly provide the magazine M for the explosive charge carriers 2, these having central openings 35 which accommodate the pipe 25 and aline with other accommodating openings in parts associated with the charge carriers as will be later described in detail. The shell parts 1b are made'of vary ing lengths to enablev the selection of the particular magazine capacity which will accord with prevailing conditions. It is preferredlthat the charge carriers as'a series be at all times under pushing pressure. The pressure medium is preferably compressed air delivered from the passage 19 into the upper portion of the magazine and acting upon a horizontal follower or pusher plate 36 slidably mounted in the magazine and having a direct bearing upon the uppermost carrier of the series. The air flow passages for the delivery of air into the magazine includes the opening 37 in the distributor 17 of suitably greater diameter than the pipe 25 and which communicates with and extends downward from the passages 19 and 20a, 20b, 20c, 20d and 20e. The wall of the opening 37 is formed with an annular rabbetted recess eittending to the underface ofthe distributor 17 in which is fitted the upper end of 'a-pipe 38 arranged in spaced concentric relation to the pipe 25 and also accommodated in the openings 35 and the associated 'alining openings. The pipes 38 and 25' delimit an annular air flow passage 39, the upper end of which isconstituted by the annular wall of the opening 37. The pipe 38 extends from the distributor 17 preferably for the remaining length of the unit and the air passage 39 is closed at its lower end by a ring 40 (Figure 5) interposed between the pipes 38 and 25 and also serving to brace these pipes to one another.

The pipe 38 has in' its upper portion a series of openings 41 through which the air flows from the passage 39 into the pressure space P of the magazine. The follower 36 has a central opening in surrounding relation to the pipe 38 and is preferably formed at the perimeter of this opening and at its periphery with raised flanges 42 and 43 which are respectivelyin suitable contact with the pipe 38 and the inner wall of the shell 1 and serve both as guides for the follower 36 and also to prevent undue loss of air from the pressure space P.

The explosive charge carriers 2 are supported by a series of movable detents 44 (Figures 5, 11, 14 and 18) provided at the lower end of the shell 1 and normally engaging the lowermost carrier 2 in the magazine, the detents 44 being operated. to disengage the lowermost carrier at the time when itis to be released from the magazine and deposited in the chargetransfer means. Immediately after the release of the lowermost carrier the detents 44 are returned to their normal positions in readiness to engage the immediately succeeding carrier which then becomes the lowermost carrier of the series. The discharge of each lowermost carrier from the magazinc and the movements of the series of carriers in stepby-step fashion upon such discharges are effected by the downward movement of the follower 36 under the pressure of air in the magazine space above.

When the last charge of the series has been detonated the unit is brought to the surface for reloading (the air and water supply of'course being cut off at the time) and the shell sections separated. If the number of charges required for the succeeding cycle remains unchanged anew seriesor clip of charges may be placed in the section 1b with the follower. plate 36 resting upon the uppermost charge and when the sections' 1b and 1c are connected the clip will drop until the lowerm'ost charge is engaged by the detents 44; or, as a time saving measure, a duplicate section 1b containing the same number of charges (held against displacement by removable tapes) may be substituted. If the number of charges required for the succeeding cycle should vary from the number required forthe preceding cycle a section 1b of greater. or less length containing the determined number of. charges is substituted. Thereupon the three sectionsv are again connected and the unit is lowered,

into, the wellbore for a repetition of the cycleof. operatioiis'. The length of the pipe 25 of course accords with "most section 1b.

The charge transfer means 45 (Figures 4 and is I in the. form of a cylinder having piston-like movement in an annular vertical Way 46 at the lower end of the shell 1. The way 46 is open at its lower end and'is delimited by the shell and a spaced concentric sleeve 47 ,lsecur'ed to the shell in any suitable manner. As shown the sleeve has an upward extension 48 of reduced internal diameter which adjoins the 'outer face of the shell and provides an internal annular shoulder 49, the sleeve having internalthreads immediately below the shoulder 49. The shell 1 is provided at a suitable elevation with a, circumscribing flange 50 against which the shoulder 49 abuts when the sleeve is properly positioned, the

flange 50 having threads for engagement by the threads of the sleeve. A ring 51 is attached to the'shell immediately below the flange 50 and is formed to provide housings for upwardly biased check valves 52 to be later described in detail, the lower face of the ring 51 constituting the upper face of the way 46.

The charge transfer cylinder 45 has at its upper end an annular head 53 which corresponds in thickness to the width of the way 46 and providesa piston responsive in downward movement to air under pressure admitted into the upper end of the way through the valves 52 and in upward movement to air under pressure admitted through certain air passages to be later described and reacting against an internal annular shoulder 54.

The cylinder 45 has at its lower end an inwardly projecting annular flange 55 which is preferably of the same vertical extent as the explosive charge carriers and receives the lowermost charge carrier from the magazine. Each charge carrier, as supported within the flange 5 5, is deposited upon the bottom of the well bore at the completion of the downward movement of the cylinder 45} The downward movement of the cylinder 45 is positively limited by means later to be described in detail.

The charge carriers are supported within the flange 55 by a suitable number, e.g., three, of clamping dogs 56 (Figures 5 and '13), mounted for radial movement in recesses 57 open to the inner face of the flange 55. The dogs 56 are normally biased inward by springs 58 reacting against the bases of the recesses 57 and thereby have engaging and clamping contact with the vertical walls of the charge carriers 2. At their inner ends the dogs '56 have circumscribing flanges 59 to which air under pressure is delivered when the cylinder 45 reaches:

its lowermost position, the dogs 56 thereby being retracted and releasing the charge. carrier for support upon the bottom of the well bore. When the charge carrier is thus released the cylinder 45 moves upward to the position inwhich it receives the succeeding-charge carrier "from the magazine. The charge carriers 2 have a verti cal annular wall 60 (Figures 13 .and 14), the external face of which preferably has a slight downward taper which conforms to' the taper. V t The detents 44 are arranged in recesses 61 extending between the inner and outer faces of the shell 1 andare mounted on vertical pivot pins62. The detents'have an operative .position in which'th'ey project slightly beyond the inner face of the shell and aninoperative I or" retracted position in which their leading edges are within the recesses 61. The detents are formedwith and the dogs 56 have their engaging faces at an incline 'acepos 64 of the lowermost charge carrier, thereby to support the series of charge carriers in the magazine. The

charge transfer cylinder 45 is formed on its inner face a short distance above the flange 55 with peripherally alining recesses 66 of V-shaped section. When' the charge transfer cylinder is in its upper position the recesses 66 accommodate the tail pieces 65 and thereby enable the retraction of the detents by the springs 63.

When the detents are retracted the lowermost charge carrier is moved from the magazine under the pressure of the follower 36 to a position within the flange 55 and is supported within the flange by the dogs 56, the sue ceeding charge carrier thereupon becoming the lowermost.

The annular wall 60 of a charge carrier 2 is shaped externally and internally to. enable the carriers to be. arranged in nested relation in the magazine. When the: charge transfer cylinder 45 commences-its downward. movement the upper walls of its recesses 66 engage the tail pieces 65 as cams and move the detents 44 to theirprojected or operative positions in which they engage in the grooves 64 of the succeeding charge carrier, now' the lowermost carrier in the series, the projected posi tions of the detents being maintained by the engagement: of the inner face of the charge transfer cylinder 45 against the tail pieces. As above noted when the charge transfer cylinder reaches its lowermost position the dogs: 56 are retracted by air pressure directed against their flanges 59 whereupon the charge carrier within the=flange 55 is released and deposited upon the bottom of the well bore.

The lower end of the flush pipe 25 is preferably in the same plane as the lower end of the shell 1. When the charge transfer cylinder 45 is in its uppermost position water from the pipe 25 discharges directly into the well bore through the central opening 35 of the lowermost charge. carrier as deposited within the flange 55. Immediately above the flange 55 the cylinder 45 is formed with openings 67 (Figure 5) extending between its inner and outer faces. During the downward movement of the cylinder 45 the openings 67 are exposed and the water from the pipe 25 flows through the openings 67 into the lower end of thetspace S through which it rises, flushing to the surface the rock detritus and the fragments of the charge carrier left from the previous detonation.

The flow of air for effecting the recipro-catory movement of the charge transfer cylinder 45, the releasing movement of the clamping dogs 56, and the venting of the operatingair to environment is prescribed by various passages to be later described in detail. Certain of these, together with their associated valves, are equidistantly spaced in .a number, e.g., three, such that the charge transfer cylinder 45 will be completely balanced in its movements. The cylinder 45, as will be later described in detail, is itself utilized as a valve in relation to certain of the airflow passages.

The distributor passages 20b, 20d and 21 extend to, vertical air passages 68 (Figures 3 and 7) having alin ing components in the several shell sectionsand being parts of the air flow paths for the admissionof air to a the upper end of the way 46, the air 'so admitted acting upon the annular head 53, of the charge transfer cylinder 45, thereby to effect its downward movement. In

a the section 10 the passages 68 communicate with short radial passages 69. (Figure 4) ,in the lower face'of the flange 50. The direct flow of air into the upper end of the way 46is from the passages 69 through alining upper and lower passages 70 and 71 (Figures 4 and 15) in the ring 51. The passages 70 are formed at their lower ends a with tapering seats 72 for the checkvalves 52 which' The wall 60 of a charge carrier 2 is formed 

